MMM V3 safe on 1717? - RC-Monster Forums

fastbaja5b · **MMM V3 safe on 1717? -** 01.25.2012, 10:27 AM

Have a 1717 in a 5T conversion, am looking at either 4s Lipo (High speed Idler) and geared for 30mph or 6s Lipo geared for 35-40mph but worried the stock esc wouldn't handle it, ripple current, MMM 6s = fire etc. Any thoughts? Should I go the MMM XL route? Is that esc safe now?

Did they ever find a way to stop the spark on connection thing? An inconvenience for some, but for ppl with an implantable defib or pacemaker, isn't it potentially hazardous? (or do we have to give up the hobby?)

d3lap · 01.25.2012, 10:38 AM

Ive seen people put the mmm and 1717 combo in buggies truggys and big mts without problem.. id imagine youd be able to run it without problems

pinkpanda3310 · 11:27 AM

If you used castle caps and a bec that would help the esc.

I take it you don't like Brian's no spark idea?

And mechanical brakes! that helps.

brian015 · 01.25.2012, 11:30 AM

Quote:

Originally Posted by pinkpanda3310

If you used castle caps and a bec that would help the esc.

I take it you don't like Brian's no spark idea?

And mechanical brakes! that helps.

Brian says that CC says not to use a resistor on a Mamba esc. If I remember correctly, it's been stated that it's Ok to use it on a Mamba if the esc is turned off when you charge the caps through the resistor - then turn the esc on.

Pdelcast · 01.25.2012, 12:45 PM

Quote:

Originally Posted by brian015

Brian says that CC says not to use a resistor on a Mamba esc. If I remember correctly, it's been stated that it's Ok to use it on a Mamba if the esc is turned off when you charge the caps through the resistor - then turn the esc on.

That's correct -- you MUST have the switch in the "off" position when powering up the caps through the resistor.

Otherwise the motor beeping THROUGH the resistor can damage the ESC over the long-term.

Kirkinsb · 01.25.2012, 05:54 PM

Quote:

Originally Posted by Pdelcast

That's correct -- you MUST have the switch in the "off" position when powering up the caps through the resistor.

Otherwise the motor beeping THROUGH the resistor can damage the ESC over the long-term.

Is the No-Spark resistor safe to use on the Mamba XL2? Reason I ask is because obvoiusly there is no switch...and the large spark you get plugging in the bullets damages them over time. And the large spark form the caps charging is quite un-nerving! I prefer the nice quiet No Spark resistor vs the large "CRACK" I get without using it. But if it is damaging my XL2, I will quit using it. The longest I leave the no-spark resistor plugged in before pluggin in the power wire is probably 1 second. I plug the power wire in right away. Let me know. Thanks Patrick. -Kirk

Pdelcast · 01.25.2012, 06:37 PM

Quote:

Originally Posted by Kirkinsb

Is the No-Spark resistor safe to use on the Mamba XL2? Reason I ask is because obvoiusly there is no switch...and the large spark you get plugging in the bullets damages them over time. And the large spark form the caps charging is quite un-nerving! I prefer the nice quiet No Spark resistor vs the large "CRACK" I get without using it. But if it is damaging my XL2, I will quit using it. The longest I leave the no-spark resistor plugged in before pluggin in the power wire is probably 1 second. I plug the power wire in right away. Let me know. Thanks Patrick. -Kirk

XL2 is OK for use with a resistor - -just not Mamba Max Pro or Mamba Monster.

magicald · 01.25.2012, 08:23 PM

What ohm resistor are you guys using...placed in series with the positive side or parallel? I think XPS sells one...

Pdelcast · 01.25.2012, 08:28 PM

Quote:

Originally Posted by magicald

What ohm resistor are you guys using...placed in series with the positive side or parallel? I think XPS sells one...

1 ohm. 5 watts minimum.

magicald · 01.25.2012, 08:33 PM

Series or parallel?

BrianG · 01.25.2012, 08:43 PM

series

fastbaja5b · 01.25.2012, 10:37 PM

Ok so I can use a no spark thing on the XL, that's good to know, so am I to take it that the consensus is that the 1717 on 4s Lipo using the high speed idler is less than ideal and I should go 6s, gear more conservatively (say 35-40mph) to keep the amps down? Won't I then perhaps have the issue of an undergeared brushless motor running hot?

BrianG · 01.25.2012, 11:13 PM

I guess I'm going to have to amend that page. I knew about using the resistor as long as the switch is off, but didn't say that on my page because I thought it was a "secret", and didn't want Patrick mad at me.

fastbaja5b: The 1717 is pretty low kv for 4s. To get any kind of speed, it has to be geared up, which does draw more current. So yeah, I would run 6s and gear more conservatively. And undergeared motor doesn't necessarily run hot - I find it's more about running the motor at WOT for extended time at any voltage. It just seems motors "like" more partial throttle running with limited top speed running. Probably something to do with how the PWM signal plays with the motor coils...

fastbaja5b · 02.01.2012, 08:52 PM

Ok, silly q time, we say the esc has to be in switch off to use the no spark (makes sense) but my XL2 has no power switch (that I can see) so how does that work? Can I therefore not use a no spark resistor?

josh9mille · 02.01.2012, 08:56 PM

Quote:

Originally Posted by fastbaja5b

Ok, silly q time, we say the esc has to be in switch off to use the no spark (makes sense) but my XL2 has no power switch (that I can see) so how does that work? Can I therefore not use a no spark resistor?

Check out post #7